3D Forward Modeling Of The TEM Method In Consideration Of IP Effect

Transient electromagnetic method belonging to the time domain electromagnetic method, which uses the power source or magnetic component sends a pulse to the ground. Its first pulse excitation, the subsurface conductivity and permeability due to differences over time will produce two induction sub-fields. Because it is in the off-field measurements after the first pure secondary field, there is no interference in a field, resulting in the rapid development, in which the observed secondary field. The field through multiple excitation sources and at different times through the observation window. You can get a different ground structure information, but also because the important difference in terms of noise sources which has many advantages compared to the frequency domain electromagnetic method. Transient electromagnetic method of flexible working device, including with point loop, large loop, galvanic source, aviation, wells and other work equipment. It has a low resistivity body responsive, vertical and horizontal, high resolution, easy construction and high efficiency are many advantages Therefore in the field of energy, mining, engineering, environmental and other widely used geophysical methods.In this paper, The use of a vertical magnetic dipole source and a horizontal electric dipole source as the field source. In the three-dimensional forward modeling, starting from the Maxwell equations, the electromagnetic field into primary and secondary field, the use of Hankel transform computing primary field, staggered sampling frequency domain finite difference method to calculate the secondary field, Then consider adding IP effect of Cole-Cole model, and finally the results obtained when the frequency domain by frequency conversion into the time domain, Compared the different polarization, the time-domain frequency response correlation coefficients obtained results, related to the final conclusion, and analyzed.In this paper, Using Fortran language in the programming and Matlab language visualizing the results.